Joseph Henry Maiden

AbstractPremiseBiotic disjunctions have attracted scientific attention for the past 200 years. Despite being represented in many familiar plants (such as bald cypress, flowering dogwood, sweetgum, partridgeberry, etc.), the eastern North American (ENA)–Mexican (M) disjunction remains poorly understood. Major outstanding questions include the divergence times of taxa exhibiting the disjunction and environmental/geological processes that may underlie the disjunction. Symphyotrichum Nees (Asteraceae), one of the most diverse genera in the eastern USA, displays several examples of disjunct ENA–M taxa.MethodsWe generated target capture data using the Angiosperms353 baitset and generated the first well‐sampled phylogenomic hypothesis for Symphyotrichum and its close relatives. Focusing on S. subgenus Virgulus, we used MCMCTREE to perform divergence time estimation and the R package BioGeoBEARS to infer ancestral regions and biogeographic transitions between North America and Mexico. Finally, we used the ancestral niche reconstruction method Utremi to test for a role of historical aridification in generating the disjunction.ResultsOur molecular data suggest a recent radiation of Symphyotrichum at the Plio‐Pleistocene boundary (~2.5 mya), with early connections to Mexico in ancestral lineages that closed off shortly after and were followed by vicariance across this region. Except for some present‐day broadly distributed species, there is a complete lack of movement between ENA and M after ~0.5 mya.ConclusionsA reconstructed disjunct distribution of suitable habitat in Pleistocene climatic models corroborates results from biogeographic modeling and confirms glacial cycles are more likely to be associated with the breakup of ENA–M biogeographic connections.

Context Mapping the distribution of species from the genus Metrosideros is crucial for developing surveillance and management plans associated with species conservation in response to issues such as rapid ‘ōhi‘a death spread in the south-central Pacific region. Aims To support this endeavour, we recognised there was a need for open and reliable geographic information system data on island locations, extents, and occurrence data of Metrosideros species. Methods Using an open science framework, we reviewed six sources of island data and five sources of species occurrence data for availability, accuracy, and licencing criteria. Key results OpenStreetMap emerged as the optimal island location data, offering accuracy, precision, and open licencing, with this data improved and reprojected for mapping purposes. The Global Biodiversity Information Facility provided the majority of Metrosideros species occurrence data, but analysis of occurrence data from iNaturalist revealed common mis-identifications with regional biases that were corrected prior to compilation. The occurrence data of Metrosideros species was also supplemented by vegetation plot data, with HAVPlot and sPlotOpen providing key additional data for some species and islands. Conclusions Citizen science data via iNaturalist and OpenStreetMap formed the core of the compiled datasets. While such crowdsourced data can have quality issues, with additional crowdsourced curatorial effort these datasets will be significant and scalable sources of data into the future. Implications All compiled occurrence and GIS data are made openly available via permissive data licences to better support future biogeographical research in the south-central Pacific region.

Without appropriate and ongoing management interventions, weeds will continue to economically and environmentally disadvantage agricultural and natural ecosystems. For these management strategies to have long‐term sustained success, they need to carefully consider the biological aspects of the targeted weed. These strategies will also need to consider potential adaptations evolved by the targeted weed in response to a range of selection pressures imposed by anthropogenetic factors, climate change, changing environmental conditions, and inappropriate or unsuccessful management regimes. One group of weeds that has been observed to readily adapt to a wide range of conditions and has shown considerable challenges in their management is invasive grasses. Adding to these challenges is that several invasive grasses have also developed resistance to a range of herbicide modes of action, which, to date, has been one of the most commonly used methods of control. To address these challenges, this review explores the biology and ecology of the globally invasive annuals Echinochloa crus‐galli (Barnyard grass) and Panicum capillare (Witchgrass), and the perennial Sorghum halepense (Johnson grass) to identify (i) the most suitable management options for their control and (ii) potential research gaps that may assist in the future management direction of these species. Based on the findings of this review, it is clear that an integrated management approach that targets different aspects of the plant's biology, in combination with early detection and treatment and ongoing surveillance, is necessary for the long‐term control of these species. Although a combination of methods appears promising, further investigation still is required to evaluate their efficiency and long‐term success in a changing environment, all of which are further discussed within this review.

Accessing the rich biodiversity in tropical ecosystems has been of great interest to scientists across the globe. While several species have been underutilized despite their wide distribution, many others are faced with continuous population decline across their native range. Here, we amassed occurrence data and environmental variables to estimate the spatial distribution and habitat suitability of six important Pelargonium species whose conservation status in South Africa has been of concern. These were combined and used to project the future habitats under 2 Global Climate Models (GCMs) and 2 Scenarios (RCP 4.5 & 8.5). We overlayed our area maps and conducted a gap analysis to identify priority areas for the conservation of our focal species. Results showed a distribution pattern driven by temperature and precipitation, and unstable suitable areas by the years 2050 and 2070. Five temperature and precipitation variables (Bio2, Bio4, Bio12, Bio14, and Bio18) were identified as primary contributors to the habitat suitability of the selected Pelargonium species. Our model evaluation demonstrated a strong performance, with an AUC score >0.8, providing robust support for its replicability in monitoring the spatial distribution of other related taxa. We identified key areas for conservation activities in a bid to expand the current known habitats of the species in focus. While we leveraged SDM approach for explaining the area of occupancy and the spatial extent of Pelargonium species across in South Africa, we posit that attention should be drawn to the preservation of the remaining populations of the species and their associated habitats, towards mitigating their extinction.

Global warming is one of the biggest threats to global biodiversity causing not only changes in the patterns of precipitation and temperature but also disturbing ecological interactions. The aim of our study was to forecast the effect of climate change on the distribution of food‐deceptive orchid species whose pollination strategy relies on a strict association with pollinators and co‐occurring rewarding Faboideae plants. We used the ecological niche modeling approach to evaluate future overlap of the suitable niches of studied orchid species with the predicted distribution of their ecological partners. Models were made based on two different global circulation models (FIO, CNRM). CNRM projections predict expansion of orchids' geographical range. In contrast, FIO prediction is less optimistic, forecasting species range contraction. The studied Faboideae species showed different responses to predicted global warming with no consistent patterns in how their suitable niches might change. Most climate change projections and scenarios of the future modifications of temperature and precipitation patterns do not predict significant loss of suitable niches of Trichocolletes bees (Colletidae) pollinating Diuris species. However, global warming has the potential to disrupt interactions between the studied orchids and their co‐occurring pea plants by altering the overlap of their geographical ranges which can further disturb pollination success. CNRM projections predict an overall loss of Faboideae within the potential geographical range of Diuris brumalis. Conversely, FIO projections suggest a less extensive predicted divergence. Our simulations offer suggestions for conservation strategies of orchids and potentially for other species that have a similar pollination strategy. The areas indicated here as suitable in the future for the occurrence of all ecological partners can be important climate refugia to consider in local conservation plans. The approach used in our study can serve as a model for understanding the potential effects of climate change on the strength of the pollination system via food deception.

Dynamic yet accurate species lists for protected areas are essential for conservation and biodiversity research. Even when such lists exist, changing taxonomy, ongoing species migrations and invasions, and new discoveries of historically overlooked species mean static lists can become rapidly outdated. Biodiversity databases such as the Global Biodiversity Information Facility, and citizen science platforms such as iNaturalist, offer rapidly accessible, georeferenced data, but their accuracy is rarely tested. Here we compare species lists generated for two of the world's oldest, more famous protected areas – Yosemite National Park in California, United States and Royal National Park in New South Wales, Australia – using both automated data extraction techniques and extensive manual curation steps. We show that automated list creation without manual curation offers inflated measures of species diversity. Lists generated from herbarium vouchers required more curation than lists generated from iNaturalist, with both incorrect coordinates attached to vouchers and long-outdated names inflating voucher-based species lists. In comparison, iNaturalist data had relatively few errors, in part due to continual curation by a large community, including many botanical experts, and the frequent and automatic implementation of taxonomic updates. As such, iNaturalist will become an increasingly accurate supplementary source for automated biodiversity lists over time, but currently offers poor coverage of graminoid species and introduced species relative to showier, native taxa, and relies on continued expert contributions to identifications. At this point, researchers must manually curate lists extracted from herbarium vouchers or static park lists, and integrate these data with records from iNaturalist, to produce the most robust and taxonomically up-to-date species lists for protected areas.

AbstractInvasive alien plants cause severe global problems; therefore, determining the factors that lead to the success or failure of invasion is a critical question in the field of invasion ecology. In this study, we aimed to determine the factors underlying differences in the distribution range of alien plants in Japan by investigating why Loliummultiflorum thrives in a wide range of habitats while L.rigidum is mainly distributed on sandy beaches. We initially evaluated environmental niche suitability through species distribution modelling and subsequently examined whether species traits influence the differences in range expansion between the two species. We used MaxEnt modelling to identify potential environmental niches for both species. The analysis revealed that L.rigidum was considerably less suited to the Japanese climate compared to L.multiflorum, with high summer precipitation in Japan identified as one of the climatic factors limiting the distribution of L.rigidum. Given that these winter annual plants remain dormant as seeds during summer, in subsequent experiments, we buried seeds in paddy field soil and sandy beach sand during summer and evaluated their survival rate in autumn. The survival rate of L.rigidum seeds was significantly lower than that of L.multiflorum, particularly in paddy soil. Factors contributing to seed mortality may include the decay or early germination of L.rigidum seeds under Japan’s high rainfall conditions. This study emphasises the importance of considering local environmental factors alongside climate niche modelling in the risk assessment of invasive species. Moreover, the integration of species distribution modelling for large-scale evaluations and manipulation experiments for fine-scale assessments proved effective in identifying climatic conditions and species traits influencing the success or failure of alien species invasion.

Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae, comprising approximately 520 species from the Northern Hemisphere. A comprehensive infrageneric classification, supported by robust phylogenetic trees and corroborated by morphological and other data, has not yet been published. For the first time, we recovered a well-resolved nuclear phylogeny of Saussurea consisting of four main clades, which was also supported by morphological data. Our analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear conflict in Saussurea, and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of Saussurea. Based on the nuclear phylogeny obtained and morphological characters, we proposed a revised infrageneric taxonomy of Saussurea, which includes four subgenera and 13 sections. Specifically, 1) S. sect. Cincta, S. sect. Gymnocline, S. sect. Lagurostemon, and S. sect. Strictae were moved from S. subg. Saussurea to S. subg. Amphilaena, 2) S. sect. Pseudoeriocoryne was moved from S. subg. Eriocoryne to S. subg. Amphilaena, and 3) S. sect. Laguranthera was moved from S. subg. Saussurea to S. subg. Theodorea.

Identifying areas susceptible to invasion by an alien species is a strategy of prevention. We used national herbaria and global databases to assess the invasion trends of the two aquatic invasive species Ludwigia hexapetala and Ludwigia peploides subsp. montevidensis in Italy. We defined the invasion status with invasion curves and predicted potentially suitable areas with Species Distribution Models based on WorldClim variables and the human footprint index. Low seasonal variation in temperature and precipitation, temperature ≥ 20 °C in the driest period of the year and low precipitation in the coldest period are the bioclimatic factors that most account for the potential distribution of the two species. The human footprint has a lower relative importance than bioclimatic variables. All Italian peninsula appears as a suitable bioclimatic environment for the invasion of the two Ludwigia species, with over 90% of areas with high suitability lying below 600 m altitude. Only mountain regions and the islands appear less suitable. The agricultural land at the foothill of the Appennine in the Mediterranean region is the most vulnerable to the invasion. Considering the trend of the invasion curves, which have been sharply rising for the latest decades, there are reasons to expect that the alien Ludwigia species will continue their expansion, if no timely and effective actions are taken. Informative campaigns, accurate monitoring and prompt management are fundamental preventive tools in areas predicted as vulnerable to invasion by this study.

ABSTRACTAimFerns are globally distributed, yet the number of studies examining the historical evolution of African taxa is relatively low. Investigation of the evolution of African fern diversity is critical in order to understand patterns and processes that have global relevance (e.g., the pantropical diversity disparity [PDD] pattern). This study aims to examine when and from where a globally distributed fern lineage arrived in sub‐Saharan Africa, to obtain a better understanding of potential processes contributing to patterns of diversity across the region.LocationGlobal, sub‐Saharan Africa.TaxonAsplenium (Aspleniaceae).MethodsWe analysed five loci from 537 Asplenium taxa using a maximum likelihood (IQ‐Tree) phylogenetic framework. For age estimation, we performed penalised likelihood as implemented in treePL, and executed a Bayesian analysis using BEAST. Biogeographical analyses were carried out using BioGeoBEARS.ResultsMost dispersals into Africa occurred within the last ~55 myr, with the highest diversity of sub‐Saharan African taxa concentrated in two clades, each of which descended from an Asian ancestor. Additional dispersals to sub‐Saharan Africa can be found throughout the phylogeny. Lastly, potential cryptic species diversity exists within Asplenium as evidenced by several polyphyletic taxa.Main ConclusionsWe recover multiple dispersals of Asplenium to sub‐Saharan Africa, with two major lineages likely diversifying after arrival.